Thief

The pairing of the Intel Core i5-9400 with the AMD Radeon RX 7900 XT in Thief presents a classic case of a high-end GPU being held back by a mid-range processor, but the results show that the bottleneck varies significantly depending on resolution. At 1080p, the system achieves an average of 99.4 FPS on High settings, but this jumps to 120.2 FPS on Low, indicating that the CPU is the primary limiter at lower graphical loads. However, as resolution increases to 4K, the frame rates compress dramatically, with the High preset delivering 62.3 FPS and the Low preset 88.5 FPS, showing that the GPU becomes the dominant constraint at higher pixel counts. This behavior is typical for a game from 2014, where the CPU requirements are fixed but the GPU workload scales directly with resolution, making the RX 7900 XT's massive 800.0 GB/s memory bandwidth and 51.48 TFLOPS of FP32 performance increasingly relevant as pixel count rises.

Resolution Scaling

The measured FPS data reveals a clear shift in system behavior as resolution climbs from 1920x1080 to 3840x2160. At 1080p with Low settings, the system hits 120.2 FPS, but this drops to 88.5 FPS at 4K — a reduction of 31.7 FPS, or about 26%. In contrast, the High preset shows a smaller absolute drop of 37.1 FPS (from 99.4 to 62.3), but a similar relative decline of roughly 37%. The Medium settings tell the most telling story: 106.7 FPS at 1080p falls to 81.4 FPS at 4K, while Ultra goes from 96.0 to 62.3 FPS. The fact that the 4K High and Ultra results are identical (62.3 FPS) suggests that the Ultra preset is not adding meaningful GPU work over High in this title, or that the system is hitting a hard performance ceiling.

This pattern indicates that at 1080p, the Core i5-9400's six threads are the limiting factor, as evidenced by the 120.2 FPS Low result being far below what the RX 7900 XT could theoretically produce. The GPU's percentile ranking of 82 versus all GPUs, combined with an average benchmark score of 38358, places it well above the CPU's 50th percentile ranking, confirming the imbalance. By 1440p, the gap between Low (103.2 FPS) and Ultra (87.8 FPS) narrows to 15.4 FPS, showing the GPU starting to take on more of the workload. At 4K, the spread between Low and Ultra shrinks further to 26.2 FPS (88.5 vs 62.3), which is still substantial but demonstrates that the GPU is now firmly in charge. The data indicates that for smooth 4K gameplay, the High preset is the practical ceiling, as it matches Ultra exactly while presumably offering lower visual fidelity demands.

FAQ

Q: What is the best resolution for this CPU-GPU combo in Thief?

A: The data shows that 1440p provides the best balance, with the High preset delivering 88.9 FPS and even Ultra maintaining a playable 87.8 FPS. At 4K, the system drops to 62.3 FPS on High/Ultra, which is below the 60 FPS threshold for many gamers, while 1080p leaves performance on the table due to CPU limits.

Q: Does the CPU bottleneck the GPU at 1080p?

A: Yes. The 120.2 FPS result at 1080p Low is the highest score in the entire dataset, but the RX 7900 XT is capable of far more based on its 82nd percentile ranking. The Core i5-9400's six cores and six threads, with a boost clock of 4.10 GHz, cannot feed the GPU fast enough to achieve higher frame rates at this resolution.

Q: How does the Ultra preset compare to High at 4K?

A: The measured average FPS is identical for both presets at 62.3 FPS. This suggests that either the Ultra settings do not add significant GPU load in Thief at 4K, or the system is hitting a performance ceiling that is not related to the GPU's raw capabilities.

Q: Is the RX 7900 XT overkill for this older game?

A: Not at 4K. The GPU's 20 GB of GDDR6 memory and 320-bit bus width are well-suited for high-resolution textures, but the 62.3 FPS High result shows that even this powerful card cannot guarantee 60+ FPS at 4K with this CPU. At 1080p, however, the GPU is clearly underutilized.

Q: What is the frame rate difference between Low and Ultra at 1440p?

A: The Low preset averages 103.2 FPS, while Ultra averages 87.8 FPS — a difference of 15.4 FPS. This is a smaller gap than at 1080p (24.2 FPS difference), indicating that the GPU is becoming more of a factor at this resolution.

Q: How does this combo rank among all tested combinations?

A: It ranks 894 out of 1642 tested combos, placing it in the lower-middle tier of the database. This is a reflection of the CPU's 50th percentile standing holding back the GPU, which alone ranks in the 82nd percentile.

Settings Recommendations

For the best experience in Thief, the data points to the High preset as the optimal choice across all resolutions. At 1080p, High delivers 99.4 FPS, which is only 3.4 FPS below Medium (106.7 FPS) and 3.4 FPS above Ultra (96.0 FPS), making it the sweet spot for visual quality versus performance. At 1440p, High hits 88.9 FPS, which is nearly identical to Ultra's 87.8 FPS but likely with lower GPU load, giving headroom for stability. The most compelling argument for High comes at 4K, where it matches Ultra exactly at 62.3 FPS — selecting High over Ultra provides the same frame rate with no visual penalty in this test.

The Low preset is not recommended for any resolution above 1080p, as the gains are marginal: at 1440p, Low offers 103.2 FPS versus High's 88.9 FPS, but the visual downgrade is significant for a stealth game where spotting enemies in shadows matters. At 4K, Low's 88.5 FPS is 26.2 FPS higher than High, but the graphical compromise undermines the immersion that Thief relies on. Medium settings are a reasonable middle ground at 4K (81.4 FPS) if the user values frame rate over fidelity, but the 19.1 FPS difference between Medium and High at 4K does not justify the visual loss. The data clearly indicates that High is the intended baseline for this hardware combination, offering the best balance of quality and playability, with Ultra providing no additional benefit at 4K.

How This Combo Ranks

With a rank of 894 out of 1642 tested combos, this pairing sits just above the median in the database, which is surprising given the GPU's strength. The RX 7900 XT alone ranks in the 82nd percentile among all GPUs, with an average benchmark score of 38358, placing it near the NVIDIA GeForce RTX 5080 Mobile (38349) and just ahead of the NVIDIA CMP 70HX (38225). However, the Core i5-9400's 50th percentile ranking and average score of 2305 drags the combo down, as it is nearly identical to the Intel Core i3-10305 (2300) and Intel Core i3-1125G4 (2299), with a delta of only 0.2% from both.

This rank of 894 reflects the fundamental imbalance in the system. In Thief, a game that is not heavily threaded, the CPU's six cores and six threads are sufficient to maintain playable frame rates, but they cap the GPU's potential. The combo's performance in the measured FPS data confirms this: the 4K Ultra result of 62.3 FPS is far below what the GPU could deliver if paired with a stronger processor. The rank suggests that users with this combo should not expect top-tier results in CPU-bound scenarios, but the system still outperforms many other combinations in the database, particularly at higher resolutions where the GPU can stretch its legs.

CPU Role

The Intel Core i5-9400 is a six-core, six-thread processor based on the Coffee Lake architecture, built on a 14 nm process node. It has a base clock of 2.90 GHz and a boost clock of 4.10 GHz, with 9 MB of shared L3 cache. Its benchmark scores are modest: a Cinebench R23 multicore score of 7969 and a single-core score of 1125, placing it in the 50th percentile of all CPUs. In Thief, the CPU's role is to feed the GPU with draw calls and game logic, and the data shows that it struggles to keep up at 1080p.

The 1080p Low result of 120.2 FPS is likely near the CPU's maximum frame rate ceiling, as the GPU is barely stressed at that resolution. The 4.10 GHz boost clock helps maintain single-thread performance, which is critical for a 2014 game that may not utilize all six threads efficiently. However, the CPU's 42.7 GB/s memory bandwidth and dual-channel DDR4 support are adequate but not exceptional. The nearest rival data shows the i5-9400 is virtually tied with the Intel Core i3-10305 and i3-1125G4, indicating that its performance class is closer to modern i3 parts than to higher-end i5 or i7 chips. In Thief, the CPU's limitation manifests as a roughly 20 FPS difference between 1080p Low and 4K Low, confirming that the processor is the bottleneck at lower resolutions.

Measured FPS Breakdown

At 1920x1080, the system delivers its highest frame rates, with Low settings averaging 120.2 FPS, Medium at 106.7 FPS, High at 99.4 FPS, and Ultra at 96.0 FPS. The spread of 24.2 FPS between Low and Ultra indicates that the CPU is the primary constraint, as the GPU has ample headroom at this resolution. The 1440p results show a tighter grouping: Low at 103.2 FPS, Medium at 93.0 FPS, High at 88.9 FPS, and Ultra at 87.8 FPS, with a spread of 15.4 FPS. The 4K results are the most GPU-bound: Low at 88.5 FPS, Medium at 81.4 FPS, High at 62.3 FPS, and Ultra at 62.3 FPS, with a spread of 26.2 FPS.

The identical High and Ultra results at 4K (both 62.3 FPS) are the most notable anomaly in the dataset, suggesting that the Ultra preset does not increase GPU load in this title at this resolution, or that the system is capped by another factor. The progression from 1080p to 4K shows a consistent decline in frame rates for each preset, with the largest drop occurring between 1440p High (88.9 FPS) and 4K High (62.3 FPS) — a 26.6 FPS reduction. The data also shows that the Low preset at 4K (88.5 FPS) is nearly as fast as the High preset at 1440p (88.9 FPS), which further illustrates the GPU's ability to handle high pixel counts when the CPU is not the limiting factor. Overall, the measured FPS breakdown confirms that this combo is best suited for 1440p gaming, where it can maintain high frame rates across all presets, while 4K requires dropping to Medium (81.4 FPS) for a comfortable experience.